Uncertainty in Measurement of the Maximum Cutting Tool Temperature by Infrared Thermography

Published:

June 13, 2014

Abstract:

This paper presents an analysis of the uncertainty in measurement of the peak temperature on the side face of a cutting tool by infrared thermography. An analytical method uses the temperature measurement equation to study the uncertainty arising from uncertainties in input variables. A Monte Carlo simulation expands on the analytical method, studying uncertainties due to additional sources such as point spread function of the optics, difference in emissivity of the chip and tool, and motion blur. The uncertainties in cutting tool emissivity and point spread function (PSF) of the imaging system are the two biggest source of uncertainty in measured peak temperature. To reduce the significant underestimation bias due to PSF, image deconvolution is adopted. Even so, a typical measurement results in an expanded uncertainty of U = 50.2 °C (k=2) in the peak cutting tool temperature. Increased optical magnification with a sharper PSF can help reduce the uncertainty.